Freezing device

ABSTRACT

An object of the present invention is to continue operation as it is without inducing any degradation of performance of a compressor even if one of compressors is broken down in a refrigeration apparatus which can freely cool or warm the inside of a room, cool a refrigerating show case and cool a freezing show case. A refrigeration apparatus ( 1 ) comprises a non-inverter compressor ( 2 A), a first inverter compressor ( 2 B) and a second inverter compressor ( 2 C). If the first inverter compressor ( 2 B) is broken down during a cooling/freezing operation in which a cooling operation is performed by an inside heat exchanger ( 41 ), a refrigerating heat exchanger ( 45 ) and a freezing heat exchanger ( 51 ), the operation is continued by opening a solenoid valve ( 7 a) disposed on a first sub pipe ( 23 ).

TECHNICAL FIELD

[0001] The present invention relates to a refrigeration apparatus and,more particularly, to a refrigeration apparatus provided with anair-conditioning heat exchanger and a cooling heat exchanger.

BACKGROUND ART

[0002] A refrigeration apparatus has been conventionally used widely asan air conditioner for cooling or warming a room, or a cooler for arefrigerant for stocking foods and the like therein. There has also beena refrigeration apparatus for performing both of air-conditioning andfreezing, as disclosed in WO 98/45651. The refrigeration apparatus ofthis type is installed at a place at which both of air-conditioning andfreezing are required, for example, at a convenience store or the like,and it is provided with a plurality of compressors and a plurality ofheat exchangers on a using side such as an air-conditioning heatexchanger and a refrigerating heat exchanger. Therefore, both of theair-conditioning inside the store and the cooling of a show case or thelike can be achieved by the use of the single refrigeration apparatus ofthis type.

[0003] However, in the case where either one of the compressors isbroken down in the conventional refrigeration apparatus, there has beena tendency of the degradation of either one of the air-conditioning heatexchanger and the refrigerating heat exchanger or of the entiredegradation of both of the heat exchangers.

[0004] In view of this, a demand has been increased for a refrigerationapparatus, in which operation can be continued as it is without inducingexcessive degradation even if one of the compressors is broken down.

[0005] In general, it is more important to maintain the freezingperformance than to maintain the air-conditioning performance in theusage requiring both of the air-conditioning and the freezing. This isbecause the degradation of the air-conditioning performance merelyinduces an uncomfortable feeling of a resident but the degradation ofthe freezing performance leads to the degradation of a quality of anobject to be cooled (e.g., frozen foods and the like). However, theconventional refrigeration apparatus has not been configured such thatthe operation is changed so as to secure the freezing performance whenthe compressor is broken down. Therefore, there has been a demand for arefrigeration apparatus in which the operation can be continued whilesecuring the freezing performance even if one of the compressors isbroken down.

[0006] The present invention has been accomplished to solve theabove-described problems experienced by the prior art. An object of thepresent invention is to provide a refrigeration apparatus in whichoperation can be continued as it is even if one of compressors is brokendown.

DISCLOSURE OF THE INVENTION

[0007] A first refrigeration apparatus comprises: a refrigerant circuitincluding first, second and third compressors juxtaposed to each other,a heat exchanger on the side of a heat source, an air-conditioning heatexchanger for air-conditioning the inside of a room, cooling heatexchangers for cooling the insides of a refrigerator and a freezer, anda first expanding mechanism and second expanding mechanisms forexpanding a refrigerant; and breakdown detecting means for detecting thebreakdown of at least the second compressor; the refrigeration apparatusbeing capable of freely performing at least a cooling operation and afreezing operation, wherein the cooling operation is performed byactuating the second compressor and the third compressor, the coolingoperation being achieved by condensing a refrigerant discharged from thesecond compressor and the third compressor by means of the beatexchanger on the side of the heat source, expanding it by the firstexpanding mechanism, evaporating it by the air-conditioning heatexchanger, and returning it to the second compressor and the thirdcompressor, and further, the freezing operation is performed byactuating the first compressor and the second compressor, the freezingoperation being achieved by condensing a refrigerant discharged from thefirst compressor and the second compressor by means of the beatexchanger on the side of the heat source, expanding it by the secondexpanding mechanisms, evaporating it by the cooling heat exchangers, andreturning it to the first compressor and the second compressor; and thecooling operation being continued by actuating the first compressor inplace of the second compressor if the breakdown of the second compressoris detected during the cooling operation.

[0008] A second refrigeration apparatus comprises: a refrigerant circuitincluding first, second and third compressors juxtaposed to each other,a heat exchanger on the side of a heat source, an air-conditioning heatexchanger for air-conditioning the inside of a room, cooling heatexchangers for cooling the insides of a refrigerator and a freezer, anda first expanding mechanism and second expanding mechanisms forexpanding a refrigerant; and breakdown detecting means for detecting thebreakdown of at least the second compressor; the refrigeration apparatusbeing capable of freely performing at least a freezing operation and acooling/freezing operation, wherein the freezing operation is performedby actuating the first compressor and the second compressor, thefreezing operation being achieved by condensing a refrigerant dischargedfrom the first compressor and the second compressor by means of the heatexchanger on the side of the heat source, expanding it by the secondexpanding mechanisms, evaporating it by the cooling heat exchangers, andreturning it to the first compressor and the second compressor, andfurther, the cooling/freezing operation is performed by actuating thefirst compressor, the second compressor and the third compressor, thecooling/freezing operation being achieved by condensing a refrigerantdischarged from the first compressor, the second compressor and thethird compressor by means of the heat exchanger on the side of the heatsource, reducing the pressure of a part of the condensed refrigerantdown to a first low pressure by the first expanding mechanism,evaporating it by the air-conditioning heat exchanger, and returning itto the third compressor while reducing the pressure of the residualcondensed refrigerant down to a second low pressure lower than the firstlow pressure by the second expanding mechanisms, evaporating it by thecooling heat exchangers, and returning it to the first compressor andthe second compressor; the refrigerant circuit further including arefrigerant pipeline for introducing the refrigerant from pipelines onthe suction sides of the first compressor and the second compressor to apipeline on the suction side of the third compressor, and channelswitching means disposed on the refrigerant pipeline; and the freezingoperation being continued by opening the channel switching means, andfurther, actuating the third compressor in place of the secondcompressor if the breakdown of the second compressor is detected duringthe freezing operation.

[0009] A third refrigeration apparatus comprises: a refrigerant circuitincluding first, second and third compressors juxtaposed to each other,a heat exchanger on the side of a heat source, an air-conditioning heatexchanger for air-conditioning the inside of a room, cooling heatexchangers for cooling the insides of a refrigerator and a freezer, anda first expanding mechanism and second expanding mechanisms forexpanding a refrigerant; and breakdown detecting means for detecting thebreakdown of at least the second compressor; the refrigeration apparatusbeing capable of freely performing at least a freezing operation and acooling/freezing operation, wherein the freezing operation is performedby actuating the first compressor and the second compressor, thefreezing operation being achieved by condensing a refrigerant dischargedfrom the first compressor and the second compressor by means of the heatexchanger on the side of the heat source, expanding it by the secondexpanding mechanisms, evaporating it by the cooling heat exchangers, andreturning it to the first compressor and the second compressor, andfurther, the cooling/freezing operation is performed by actuating thefirst compressor, the second compressor and the third compressor, thecooling/freezing operation being achieved by condensing a refrigerantdischarged from the first compressor, the second compressor and thethird compressor by means of the heat exchanger on the side of the heatsource, reducing the pressure of a part of the condensed refrigerantdown to a first low pressure by the first expanding mechanism,evaporating it by the air-conditioning heat exchanger, and returning itto the third compressor while reducing the pressure of the residualcondensed refrigerant down to a second low pressure lower than the firstlow pressure by the second expanding mechanisms, evaporating it by thecooling heat exchangers, and returning it to the first compressor andthe second compressor; the refrigerant circuit further including arefrigerant pipeline for introducing the refrigerant from pipelines onthe suction sides of the first compressor and the second compressor to apipeline on the suction side of the third compressor, and channelswitching means disposed on the refrigerant pipeline; and thecooling/freezing operation being continued by opening the channelswitching means, and further, by condensing the refrigerant dischargedfrom the first compressor and the third compressor by means of the heatexchanger on the side of the heat source, reducing the pressure down toa predetermined pressure lower than the first low pressure by the firstexpanding mechanism and the second expanding mechanisms, respectively,evaporating it by the air-conditioning heat exchanger and the coolingheat exchangers, and returning it to the first compressor and the thirdcompressor if the breakdown of the second compressor is detected duringthe cooling/freezing operation.

[0010] A fourth refrigeration apparatus comprises: a refrigerant circuitincluding first, second and third compressors juxtaposed to each other,a heat exchanger on the side of a heat source, an air-conditioning heatexchanger for air-conditioning the inside of a room, cooling heatexchangers for cooling the insides of a refrigerator and a freezer, anda first expanding mechanism and second expanding mechanisms forexpanding a refrigerant; and breakdown detecting means for detecting thebreakdown of at least the third compressor; the refrigeration apparatusbeing capable of freely performing at least a freezing operation and acooling/freezing operation, wherein the freezing operation is performedby actuating the first compressor and the second compressor, thefreezing operation being achieved by condensing a refrigerant dischargedfrom the first compressor and the second compressor by means of the heatexchanger on the side of the heat source, expanding it by the secondexpanding mechanisms, evaporating it by the cooling heat exchangers, andreturning it to the first compressor and the second compressor, andfurther, the cooling/freezing operation is performed by actuating thefirst compressor, the second compressor and the third compressor, thecooling/freezing operation being achieved by condensing a refrigerantdischarged from the first compressor, the second compressor and thethird compressor by means of the heat exchanger on the side of the heatsource, reducing the pressure of a part of the condensed refrigerantdown to a first low pressure by the first expanding mechanism,evaporating it by the air-conditioning heat exchanger, and returning itto the third compressor while reducing the pressure of the residualcondensed refrigerant down to a second low pressure lower than the firstlow pressure by the second expanding mechanisms, evaporating it by thecooling heat exchangers, and returning it to the first compressor andthe second compressor; the refrigerant circuit further including arefrigerant pipeline for introducing the refrigerant from a pipeline onthe suction side of the third compressor to pipelines on the suctionsides of the first compressor and the second compressor, and channelswitching means disposed on the refrigerant pipeline; and thecooling/freezing operation being continued by opening the channelswitching means, and further, by condensing the refrigerant dischargedfrom the first compressor and the second compressor by means of the heatexchanger on the side of the heat source, reducing the pressure down toa predetermined pressure lower than the first low pressure by the firstexpanding mechanism and the second expanding mechanisms, respectively,evaporating it by the air-conditioning heat exchanger and the coolingheat exchangers and, and returning it to the first compressor and thesecond compressor if the breakdown of the third compressor is detectedduring the cooling/freezing operation.

[0011] A fifth refrigeration apparatus comprises: a refrigerant circuitincluding first, second and third compressors juxtaposed to each other,a heat exchanger on the side of a heat source, an air-conditioning heatexchanger for air-conditioning the inside of a room, cooling heatexchangers for cooling the insides of a refrigerator and a freezer, anda first expanding mechanism and second expanding mechanisms forexpanding a refrigerant; and breakdown detecting means for detecting thebreakdown of at least the second compressor; the refrigeration apparatusbeing capable of freely performing at least a warming operation and afreezing operation, wherein the warming operation is performed byactuating the second compressor and the third compressor, the warmingoperation being achieved by condensing a refrigerant discharged from thesecond compressor and the third compressor by means of theair-conditioning heat exchanger, expanding it by the first expandingmechanism, evaporating it by the heat exchanger on the side of the heatsource, and returning it to the second compressor and the thirdcompressor, and further, the freezing operation is performed byactuating the first compressor and the second compressor, the freezingoperation being achieved by condensing a refrigerant discharged from thefirst compressor and the second compressor by means of the heatexchanger on the side of the heat source, expanding it by the secondexpanding mechanisms, evaporating it by the cooling heat exchangers, andreturning it to the first compressor and the second compressor; and thewarming operation being continued by actuating the first compressor inplace of the second compressor if the breakdown of the second compressoris detected during the warming operation.

[0012] A sixth refrigeration apparatus comprises: a refrigerant circuitincluding first, second and third compressors juxtaposed to each other,a heat exchanger on the side of a heat source, an air-conditioning heatexchanger for air-conditioning the inside of a room, cooling heatexchangers for cooling the insides of a refrigerator and a freezer, anda first expanding mechanism and second expanding mechanisms and forexpanding a refrigerant; and breakdown detecting means for detecting thebreakdown of at least the second compressor; the refrigeration apparatusbeing capable of freely performing at least a warming operation and awarming/freezing operation, wherein the warming operation is performedby actuating the second compressor and the third compressor, the warmingoperation being achieved by condensing a refrigerant discharged from thesecond compressor and the third compressor by means of theair-conditioning heat exchanger, expanding it by the first expandingmechanism, evaporating it by the heat exchanger on the side of the heatsource, and returning it to the second compressor and the thirdcompressor, and further, the warming/freezing operation is performed byactuating the first compressor and the second compressor, thewarming/freezing operation being achieved by condensing a part of arefrigerant discharged from the first compressor and the secondcompressor by means of the air-conditioning heat exchanger whilecondensing the residual discharged refrigerant by means of the heatexchanger on the side of the heat source, expanding both of therefrigerants by the second expanding mechanisms, evaporating them by thecooling heat exchangers, and returning them to the first compressor andthe second compressor; the refrigerant circuit further including arefrigerant pipeline for introducing the refrigerant from pipelines onthe suction sides of the first compressor and the second compressor to apipeline on the suction side of the third compressor, and channelswitching means disposed on the refrigerant pipeline; and thewarming/freezing operation being continued by opening the channelswitching means, and further, actuating the third compressor in place ofthe second compressor if the breakdown of the second compressor isdetected during the warming/freezing operation.

[0013] In a seventh refrigeration apparatus, the cooling heat exchangersinclude a refrigerating heat exchanger and a freezing heat exchanger;and

[0014] the refrigerant circuit is disposed downstream of the freezingheat exchanger, and includes an auxiliary compressor for reducing thepressure of the refrigerant inside of the freezing heat exchanger lowerthan that of the refrigerant inside of the refrigerating heat exchanger,in any one of the first to sixth refrigeration apparatuses.

[0015] An eighth refrigeration apparatus further comprises a bypass (59)passage connected at one end thereof to the discharge side of theauxiliary compressor (53) and at the other end thereof to the suctionside of the auxiliary compressor (53), for allowing the refrigerant toflow in such a manner as to bypass the auxiliary compressor (53) if theauxiliary compressor (53) is broken down, in the seventh refrigerationapparatus.

[0016] In the first refrigeration apparatus, the first compressor isdriven in place of the second compressor if the second compressor isbroken down during the cooling operation. A circulating operation isperformed such that the refrigerant discharged from the first compressorand the third compressor is condensed by the heat source side heatexchanger, is expanded by the first expanding mechanism, is evaporatedby the air-conditioning heat exchanger, and is returned to the firstcompressor and the third compressor. Thus, the cooling operation can becontinued while maintaining the cooling performance.

[0017] In the second refrigeration apparatus, the channel switchingmeans is opened, and further, the third compressor is driven if thesecond compressor is broken down during the freezing operation. Acirculating operation is performed such that the refrigerant dischargedfrom the first compressor and the third compressor is condensed by theheat source side heat exchanger, is expanded by the second expandingmechanism, is evaporated by the cooling heat exchanger, and is returnedto the first compressor and the third compressor. Thus, the freezingoperation can be continued while maintaining the freezing performance.

[0018] In the third refrigeration apparatus, the channel switching meansis opened if the second compressor is broken down during thecooling/freezing operation. A circulating operation is performed suchthat the refrigerant discharged from the first compressor and the thirdcompressor is condensed by the heat source side heat exchanger, isreduced in pressure by the first expanding mechanism and the secondexpanding mechanisms, is evaporated by the air-conditioning heatexchanger and the cooling heat exchanger, respectively, and is returnedto the first compressor and the third compressor. Thus, the refrigerantcirculating quantity in the cooling heat exchanger can be maintained. Inthe meantime, the refrigerant circulating quantity in theair-conditioning heat exchanger is reduced. However, since the pressureof the refrigerant in the air-conditioning heat exchanger is reduced,the evaporation temperature of the refrigerant in the air-conditioningheat exchanger is reduced. Consequently, it is possible to suppress thedegradation of the cooling performance of the air-conditioning heatexchanger, although the refrigerant circulating quantity is reduced.Thus, the cooling/freezing operation can be continued while maintainingat least the freezing performance.

[0019] In the fourth refrigeration apparatus, the channel switchingmeans is opened if the third compressor is broken down during thecooling/freezing operation. A circulating operation is performed suchthat the refrigerant discharged from the first compressor and the secondcompressor is condensed by the heat source side heat exchanger, isreduced in pressure by the first expanding mechanism and the secondexpanding mechanisms, is evaporated by the air-conditioning heatexchanger and the cooling heat exchanger, respectively, and is returnedto the first compressor and the second compressor. Thus, thecooling/freezing operation can be continued while maintaining at leastthe freezing performance, like the above-described third refrigerationapparatus.

[0020] In the fifth refrigeration apparatus, the first compressor isdriven in place of the second compressor if the second compressor isbroken down during the warming operation. A circulating operation isperformed such that the refrigerant discharged from the first compressorand the third compressor is condensed by the air-conditioning heatexchanger, is expanded by the first expanding mechanism, is evaporatedby the heat source side heat exchanger, and is returned to the firstcompressor and the third compressor. Thus, the warming operation can becontinued while maintaining the warming performance.

[0021] In the sixth refrigeration apparatus, the channel switching meansis opened, and further, the third compressor is driven if the secondcompressor is broken down during the warming/freezing operation. Acirculating operation is performed such that a part of the refrigerantdischarged from the first compressor and the third compressor iscondensed by the air-conditioning heat exchanger while the residualdischarged refrigerant is condensed by the heat source side heatexchanger, and further, both of the refrigerants are expanded by thesecond expanding mechanisms, are evaporated by the cooling heatexchangers, and are returned to the first compressor and the thirdcompressor. Thus, the warming/freezing operation can be continued whilemaintaining at least the freezing performance.

[0022] In the seventh refrigeration apparatus, the cooling heatexchanger includes two kinds of heat exchangers (i.e., a refrigeratingheat exchanger and a freezing heat exchanger) having differentevaporation temperatures, and therefore, an object to be cooled can becooled at two kinds of cooling temperatures.

[0023] In the eighth refrigeration apparatus, the refrigerant can bypassthe auxiliary compressor via the bypass passage if the auxiliarycompressor is broken down, thereby achieving a smooth circulation of therefrigerant.

[0024] As described above, according to the present invention, thepredetermined operation can be continued without inducing any excessivedegradation of the performance even if one of the compressors is brokendown. Thus, it is possible to enhance the reliability of the apparatus.

[0025] In particular, the operation can be continued without degradingthe cooling performance of the cooling heat exchanger in the case wherethe compressor is broken down during an operation in which the inside ofa cold store is cooled by the cooling heat exchanger (such as a freezingoperation, a cooling/freezing operation or a warming/freezingoperation), thus preventing any deterioration of a quality of the objectto be cooled.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026]FIG. 1 is a refrigerant circuit diagram of a refrigerationapparatus;

[0027]FIG. 2 is a refrigerant circuit diagram illustrating a refrigerantcirculation during a cooling operation;

[0028]FIG. 3 is a flowchart illustrating the control of the coolingoperation;

[0029]FIG. 4 is a graph illustrating a first capacity control;

[0030]FIG. 5 is a refrigerant circuit diagram illustrating a refrigerantcirculation during the cooling operation in the case where a compressoris broken down;

[0031]FIG. 6 is a graph illustrating a second capacity control;

[0032]FIG. 7 is a refrigerant circuit diagram illustrating a refrigerantcirculation during a freezing operation;

[0033]FIG. 8 is a flowchart illustrating the control of the freezingoperation;

[0034]FIG. 9 is a refrigerant circuit diagram illustrating a refrigerantcirculation during the freezing operation in the case where a compressoris broken down;

[0035]FIG. 10 is a refrigerant circuit diagram illustrating arefrigerant circulation during a cooling/freezing operation;

[0036]FIG. 11 is a Mollier chart illustrating a freezing cycle;

[0037]FIG. 12 is a refrigerant circuit diagram illustrating arefrigerant circulation during the cooling/freezing operation in thecase where a compressor is broken down;

[0038]FIG. 13 is a flowchart illustrating the control of thecooling/freezing operation in the case where the compressor is brokendown;

[0039]FIG. 14 is a flowchart illustrating the control of thecooling/freezing operation in the case where the compressor is brokendown;

[0040]FIG. 15 is a refrigerant circuit diagram illustrating arefrigerant circulation during a warming operation;

[0041]FIG. 16 is a flowchart illustrating the control of the warmingoperation;

[0042]FIG. 17 is a refrigerant circuit diagram illustrating arefrigerant circulation during the warming operation in the case where acompressor is broken down;

[0043]FIG. 18 is a refrigerant circuit diagram illustrating arefrigerant circulation during a warming/freezing operation;

[0044]FIG. 19 is a flowchart illustrating the control of thewarming/freezing operation; and

[0045]FIG. 20 is a refrigerant circuit diagram illustrating arefrigerant circulation during the warming/freezing operation in thecase where a compressor is broken down.

BEST MODES FOR CARRYING OUT THE INVENTION

[0046] Best modes carrying out the present invention will be describedbelow in reference to the accompanying drawings.

General Configuration of Refrigeration Apparatus

[0047] As shown in FIG. 1, a refrigeration apparatus (1) in a preferredembodiment is installed at a convenience store, and is adapted to coolthe inside of a storage, i.e., a show case and warm or cool the insideof a room, i.e., the inside of the store.

[0048] The refrigeration apparatus (1) comprises an outside unit (1A),an inside unit (1B), a refrigerating unit (1C) and a freezing unit (1D),and further, includes a refrigerant circuit (1E) for performing a steamcompression type freezing cycle.

[0049] The inside unit (1B) is configured such that it can selectivelyperform a cooling operation and a warming operation, and is installedat, for example, a shop. The refrigerating unit (1C) is mounted at arefrigerating show case, so as to cool the air inside of the show case.The freezing unit (1D) is mounted at a freezing show case, so as to coolthe air inside of the show case.

Outside Unit

[0050] The outside unit (1A) is provided with a non-inverter compressor(2A), a first inverter compressor (2B) and a second inverter compressor(2C), and further, includes a first 4-way switch valve (3A), a second4-way switch valve (3B) and an outside heat exchanger (4) serving as aheat exchanger on the heat source side.

[0051] Each of the above-described compressors (2A) to (2C) isconstituted of, for example, a high pressure domed scroll compressor ofa sealing type. The non-inverter compressor (2A) is of a constantcapacity type in which an electric motor is always driven at a constantengine speed. Each of the first inverter compressor (2B) and the secondinverter compressor (2C) is of a type in which an electric motor isinverter-controlled so that its capacity can be varied stepwise orcontinuously.

[0052] The non-inverter compressor (2A), the first inverter compressor(2B) and the second inverter compressor (2C) constitute compressormechanisms of two systems, that is, a compressor mechanism (2D) of afirst system and a compressor mechanism (2E) of a second system. Thepattern of the compressors constituting the compressor mechanisms (2D)and (2E) of these two systems can be changed in an appropriate manner.That is to say, there are two cases: the non-inverter compressor (2A)and the first inverter compressor (2B) constitute the compressormechanism (2D) of the first system while the second inverter compressor(2C) constitutes the compressor mechanism (2E) of the second system; andthe non-inverter compressor (2A) constitutes the compressor mechanism(2D) of the first system while the first inverter compressor (2B) andthe second inverter compressor (2C) constitute the compressor mechanism(2E) of the second system.

[0053] Respective discharge pipes (5 a), (5 b) and (5 c) of thenon-inverter compressor (2A), the first inverter compressor (2B) and thesecond inverter compressor (2C) are connected to a single high pressuregas pipe (8), which is connected to a first port of the first 4-wayswitch valve (3A). Check valves (7) are disposed at the discharge pipe(5 a) of the non-inverter compressor (2A), the discharge pipe (5 b) ofthe first inverter compressor (2B) and the discharge pipe (5 c) of thesecond inverter compressor (2C), respectively, such that an operationcan be started by any of the compressors.

[0054] The outside heat exchanger (4) is connected at a gas side endthereof to a second port of the first 4-way switch valve (3A) via anouter gas pipe (9). In contrast, the outside heat exchanger (4) isconnected at a liquid side end thereof to one end of a liquid pipe (10)serving as a liquid line. On the way of the liquid pipe (10) is disposeda receiver (14). The other end of the liquid pipe (10) is branched to afirst connecting liquid pipe (11) and a second connecting liquid pipe(12).

[0055] The type of outside heat exchanger (4) is not particularlylimited: for example, a fin and tube heat exchanger of a cross fin typeor the like can be used preferably. In the vicinity of the outside heatexchanger (4) is disposed an outside fan (4F).

[0056] Respective suction pipes (6 a) and (6 b) of the non-invertercompressor (2A) and the first inverter compressor (2B) are connected toa low pressure gas pipe (15). A suction pipe (6 c) of the secondinverter compressor (2C) is connected to a third port of the second4-way switch valve (3B).

[0057] To a fourth port of the first 4-way switch valve (3A) isconnected a connecting gas pipe (17). A third port of the first 4-wayswitch valve (3A) is connected to a fourth port of the second 4-wayswitch valve (3B) via a connecting pipe (18). A first port of the second4-way switch valve (3B) is connected to the discharge pipe (5 c) of thesecond inverter compressor (2C) via an auxiliary gas pipe (19). A secondport of the second 4-way switch valve (3B) is a closed port which isclosed at all times. In other words, the second 4-way switch valve (3B)is a channel switch valve for appropriately connecting the three ports.Consequently, a 3-way switch valve may be used in place of the second4-way switch valve (3B).

[0058] The first 4-way switch valve (3A) is configured so as to bechanged over from a first state (see a solid line in FIG. 1) in whichthe high pressure gas pipe (8) and the outside gas pipe (9) communicatewith each other and further the connecting pipe (18) and the connectinggas pipe (17) communicate with each other to a second state (see abroken line in FIG. 1) in which the high pressure gas pipe (8) and theconnecting gas pipe (17) communicate with each other and further theconnecting pipe (18) and the outside gas pipe (9) communicate with eachother, and vice versa.

[0059] In contrast, the second 4-way switch valve (3B) is configured soas to be changed over from the first state (see the solid line inFIG. 1) in which the auxiliary gas pipe (19) and the closed portcommunicate with each other and further the connecting pipe (18) and thesuction pipe (6 c) of the second inverter compressor (2C) communicatewith each other to the second state (see the broken line in FIG. 1) inwhich the auxiliary gas pipe (19) and the connecting pipe (18)communicate with each other and further the suction pipe (6 c) and theclosed port communicate with each other, and vice versa.

[0060] The above-described discharge pipes (5 a), (5 b) and (5 c), thehigh pressure gas pipe (8) and the outside gas pipe (9) constitute ahigh pressure gas line (1L) at the time of a cooling operation.Furthermore, the low pressure gas pipe (15) and the suction pipes (6 a)and (6 b) of the compressor mechanism (2D) of the first systemconstitute a first low pressure gas line (1M). Moreover, the connectinggas pipe (17) and the suction pipe (6 c) of the compressor mechanism(2E) of the second system constitute a second low pressure gas line (1N)at the time of the cooling operation.

[0061] The first connecting liquid pipe (11), the second connectingliquid pipe (12), the connecting gas pipe (17) and the low pressure gaspipe (15) extend outside of the outside unit (1A), and are provided withclosing valves (20), respectively, inside of the outside unit (1A).Additionally, at the end on the branch side of the second connectingliquid pipe (12), a check valve (7) is disposed inside of the outsideunit (1A), so as to allow a refrigerant to flow from the receiver (14)to the closing valve (20).

[0062] The low pressure gas pipe (15) and the suction pipe (6 c) of thesecond inverter compressor (2C) are connected to each other via acommunicating pipe (21) serving as an auxiliary line. The communicatingpipe (21) allows respective suction sides of the non-inverter compressor(2A), the first inverter compressor (2B) and the second invertercompressor (2C) to communicate with each other. The communicating pipe(21) includes a main pipe (22), and a first sub pipe (23) and a secondsub pipe (24), which are branched from the main pipe (22). The main pipe(22) is connected to the suction pipe (6 c) of the second invertercompressor (2C). The first sub pipe (23) and the second sub pipe (24)are connected to the low pressure gas pipe (15).

[0063] The first sub pipe (23) and the second sub pipe (24) are providedwith solenoid valves (7 a) and (7 b) serving as opening/closingmechanisms and check valves (7), respectively. That is to say, the firstsub pipe (23) is configured such that it allows the refrigerant to flowfrom the pipes on the suction sides of the non-inverter compressor (2A)and the first inverter compressor (2B) to the pipe on the suction sideof the second inverter compressor (2C). In contrast, the second sub pipe(24) is configured such that it allows the refrigerant to flow from thepipe on the suction side of the second inverter compressor (2C) to thepipes on the suction sides of the non-inverter compressor (2A) and thefirst inverter compressor (2B).

[0064] To the liquid pipe (10) is connected an auxiliary liquid pipe(25), which bypasses the receiver (14). The refrigerant flows in theauxiliary liquid pipe (25) mainly during a warming operation. Theauxiliary liquid pipe (25) is provided with an outside expanding valve(26) serving as an expanding mechanism. Between the outside heatexchanger (4) on the liquid pipe (10) and the receiver (14) isinterposed a check valve (7) for allowing only the flow of therefrigerant toward the receiver (14). The check valve (7) is locatedbetween a joint of the auxiliary liquid pipe (25) on the liquid pipe(10) and the receiver (14).

[0065] A liquid injection pipe (27) is connected between the auxiliaryliquid pipe (25) and the low pressure gas pipe (15). The liquidinjection pipe (27) is provided with a solenoid valve (7 c).Furthermore, a degassing pipe (28) is interposed between the upperportion of the receiver (14) and the discharge pipe (5 a) of thenon-inverter compressor (2A). The degassing pipe (28) is provided with acheck valve (7) for allowing only the flow of the refrigerant from thereceiver (14) toward the discharge pipe (5 a).

[0066] The high pressure gas pipe (8) is provided with an oil separator(30). To the oil separator (30) is connected one end of an oil returningpipe (31). The oil returning pipe (31) is provided with a solenoid valve(7 d), and is connected at the other end thereof to the suction pipe (6a) of the non-inverter compressor (2A). A first oil smoothing pipe (32)is connected between the dome of the non-inverter compressor (2A) andthe suction pipe (6 c) of the second inverter compressor (2C). On thefirst oil smoothing pipe (32) are disposed a check valve (7) and asolenoid valve (7 e) for allowing the flow of oil from the non-invertercompressor (2A) toward the second inverter compressor (2C).

[0067] To the dome of the first inverter compressor (2B) is connectedone end of a second oil smoothing pipe (33). The other end of the secondoil smoothing pipe (33) is connected between the check valve (7) and thesolenoid valve (7 e) of the first oil smoothing pipe (32). Moreover, athird oil smoothing pipe (34) is connected between the dome of thesecond inverter compressor (2C) and the low pressure gas pipe (15). Thethird oil smoothing pipe (34) is provided with a solenoid valve (7 f).

[0068] A floor warming circuit (35) is connected to the liquid pipe(10). The floor warming circuit (35) includes a heat exchanger (36) forwarming a floor, a first pipeline (37) and a second pipeline (38). Oneend of the first pipeline (37) is connected between the check valve (7)and the closing valve (20) on the first connecting liquid pipe (11); incontrast, the other end thereof is connected to the heat exchanger (36)for warming a floor. One end of the second pipeline (38) is connectedbetween the check valve (7) on the liquid pipe (10) and the receiver(14); in contrast, the other end thereof is connected to the heatexchanger (36) for warming a floor. The heat exchanger (36) for warminga floor is put at a register (at a checkout counter), at which a clerkworks for a long time, at a convenience store.

[0069] Closing valves (20) are disposed on the first pipeline (37) andthe second pipeline (38), respectively. The first pipeline (37) isprovided with a check valve (7) for allowing only the flow of therefrigerant toward the heat exchanger (36) for warming a floor.Incidentally, the heat exchanger (36) for warming a floor may beomitted. In the case where no heat exchanger (36) for warming a floor isprovided, the first pipeline (37) and the second pipeline (38) areconnected directly to each other.

Inside Unit

[0070] The inside unit (1B) comprises an inside heat exchanger (41)serving as a heat exchanger on a using side and an inside expandingvalve (42) serving as an expanding mechanism. The connecting gas pipe(17) is connected onto the gas side of the inside heat exchanger (41).In contrast, the second connecting liquid pipe (12) is connected ontothe liquid side of the inside heat exchanger (41) via the insideexpanding valve (42). Here, the type of inside heat exchanger (41) isnot particularly limited: for example, a fin and tube heat exchanger ofa cross fin type or the like can be used preferably. In the vicinity ofthe inside heat exchanger (41) is disposed an inside fan (43) serving asa fan on the using side.

Refrigerating Unit

[0071] The refrigerating unit (1C) comprises a refrigerating heatexchanger (45) serving as a cooling heat exchanger and a refrigeratingexpanding valve (46) serving as an expanding mechanism. The firstconnecting liquid pipe (11) is connected onto the liquid side of therefrigerating heat exchanger (45) via a solenoid valve (7 g) and therefrigerating expanding valve (46). In contrast, the low pressure gaspipe (15) is connected onto the gas side of the refrigerating heatexchanger (45).

[0072] The refrigerating heat exchanger (45) communicates with thesuction side of the compressor mechanism (2D) of the first system; incontrast, the inside heat exchanger (41) communicates with the suctionside of the second inverter compressor (2C) during the coolingoperation. Consequently, the refrigerant pressure (i.e., the evaporationpressure) of the refrigerating heat exchanger (45) normally becomeslower than that of the inside heat exchanger (41). As a result, arefrigerant evaporation temperature at the refrigerating heat exchanger(45) becomes, for example, −10° C.; in contrast, a refrigerantevaporation temperature at the inside heat exchanger (41) becomes, forexample, +5° C. In this manner, the refrigerant circuit (1E) constitutesa circuit for so-called evaporation at different temperatures.

[0073] Here, the refrigerating expanding valve (46) is a thermosensitiveexpanding valve, in which a thermosensitive cylinder is attached ontothe gas side of the refrigerating heat exchanger (45). For example, afin and tube heat exchanger of a cross fin type or the like can bepreferably used as the refrigerating heat exchanger (45). In thevicinity of the refrigerating heat exchanger (45) is disposed arefrigerating fan (47) serving as a cooling fan.

Freezing Unit

[0074] The freezing unit (1D) comprises a freezing heat exchanger (51)serving as a cooling heat exchanger, a freezing expanding valve (52)serving as an expanding mechanism and a booster compressor (53) servingas a freezing compressor. A branch liquid pipe (13) branching off fromthe first connecting liquid pipe (11) is connected onto the liquid sideof the freezing heat exchanger (51) via a solenoid valve (7 a) and thefreezing expanding valve (52).

[0075] The gas side of the freezing heat exchanger (51) and the suctionside of the booster compressor (53) are connected to each other via aconnecting gas pipe (54). Onto the discharge side of the boostercompressor (53) is connected a branch gas pipe (16) branching off fromthe low pressure gas pipe (15). On the branch gas pipe (16) are disposeda check valve (7) and an oil separator (55). Between the oil separator(55) and the connecting gas pipe (54) is connected an oil returning pipe(57) having a capillary tube (56).

[0076] The booster compressor (53) compresses the refrigerant at twostages in cooperation with the compressor mechanism (2D) of the firstsystem, so as to set a refrigerant evaporation temperature at thefreezing heat exchanger (51) lower than that at the refrigerating heatexchanger (45). The refrigerant evaporation temperature at the freezingheat exchanger (51) is set to, for example, −40° C.

[0077] Here, the freezing expanding valve (52) is a thermosensitiveexpanding valve, in which a thermosensitive cylinder is attached ontothe gas side of the freezing heat exchanger (51). For example, a fin andtube heat exchanger of a cross fin type or the like can be preferablyused as the freezing heat exchanger (51). In the proximity of thefreezing heat exchanger (51) is disposed a freezing fan (58) serving asa cooling fan.

[0078] Additionally, a bypass pipe (59) having a check valve (7) isconnected between the connecting gas pipe (54) on the suction side ofthe booster compressor (53) and the downstream side of the check valve(7) of the branch gas pipe (16) on the discharge side of the boostercompressor (53). The bypass pipe (59) is adapted to allow therefrigerant to flow while bypassing the booster compressor (53) if thebooster compressor (53) accidentally stops due to a breakdown or thelike.

Control System

[0079] The refrigerant circuit (1E) includes various kinds of sensorsand various kinds of switches. On the high pressure gas pipe (8) in theoutside unit (1A), there are provided a high pressure sensor (61)serving as pressure detecting means for detecting the pressure of a highpressure refrigerant and a discharge temperature sensor (62) serving astemperature detecting means for detecting the temperature of a highpressure refrigerant. On the discharge pipe (5 c) of the second invertercompressor (2C), there is provided a discharge temperature sensor (63)serving as temperature detecting means for detecting the temperature ofa high pressure refrigerant. Furthermore, pressure switches (64), whichare actuated when the pressure of the high pressure refrigerant exceedsa predetermined value, are provided on the discharge pipes (5 a), (5 b)and (5 c) of the non-inverter compressor (2A), the first invertercompressor (2B) and the second inverter compressor (2C), respectively.

[0080] On the suction pipes (6 b) and (6 c) of the first invertercompressor (2B) and the second inverter compressor (2C), there areprovided low pressure sensors (65) and (66) serving as pressuredetecting means for detecting the pressure of a low pressure refrigerantand suction temperature sensors (67) and (68) serving as temperaturedetecting means for detecting the temperature of a low pressurerefrigerant, respectively.

[0081] The outside heat exchanger (4) includes an outside heat exchangetemperature sensor (69) serving as temperature detecting means fordetecting an evaporation temperature or a condensation temperature asthe temperature of the refrigerant in the outside heat exchanger (4).Moreover, the outside unit (1A) includes an outside air temperaturesensor (70) serving as temperature detecting means for detecting thetemperature of an outside air.

[0082] The inside heat exchanger (41) includes an inside heat exchangetemperature sensor (71) serving as temperature detecting means fordetecting a condensation temperature or an evaporation temperature asthe temperature of the refrigerant in the inside heat exchanger (41),and a gas temperature sensor (72) serving as temperature detecting meansfor detecting the temperature of a gaseous refrigerant on the gas sideof the inside heat exchanger (41). Moreover, the inside unit (1B)includes an inside air temperature sensor (73) serving as temperaturedetecting means for detecting the temperature of an inside air.

[0083] The refrigerating unit (1C) includes a refrigerating temperaturesensor (74) serving as temperature detecting means for detecting thetemperature inside of the refrigerating show case. The freezing unit(1D) includes a freezing temperature sensor (75) serving as temperaturedetecting means for detecting the temperature inside of the freezingshow case.

[0084] The second pipeline (38) in the floor warming circuit (35)includes a liquid temperature sensor (76) serving as temperaturedetecting means for detecting the temperature of the refrigerant whichhas flowed through the heat exchanger (36) for warming the floor.

[0085] Output signals from the various sensors and the various switchesare input into a controller (80). The controller (80) is configured suchthat it can control the capacities and the like of the first invertercompressor (2B) and the second inverter compressor (2C).

[0086] Furthermore, the controller (80) includes a breakdown detectingunit for detecting the breakdown of each of the compressors (2A), (2B)and (2C). The well-known technique can be used for detecting thebreakdown of the compressor: for example, a breakdown can be detectedbased on an overcurrent, a discharge refrigerant temperature or the likeof each of the compressors (2A), (2B) and (2C). A breakdown judgingmethod also is not limited in particular: for example, a breakdown maybe judged if abnormality in terms of the compressor occurs fiveconsecutive times at the time of starting.

[0087] The controller (80) is configured such that it not only detectsthe breakdown of the compressor, but also carries out variousoperations, described below, and controls to switch the operations.

Cooling Operation

[0088] In a cooling operation, the inside unit (1B) is actuated toperform only a cooling operation. During the cooling operation, thenon-inverter compressor (2A) constitutes the compressor mechanism (2D)of the first system while the first inverter compressor (2B) and thesecond inverter compressor (2C) constitute the compressor mechanism (2E)of the second system, as illustrated in FIG. 2, and only the firstinverter compressor (2B) and the second inverter compressor (2C)constituting the compressor mechanism (2E) of the second system aredriven.

[0089] As indicated by a solid line in FIG. 2, each of the first 4-wayswitch valve (3A) and the second 4-way switch valve (3B) are switched tothe first state. The solenoid valve (7 b) disposed on the second subpipe (24) of the communicating pipe (21) is opened. In the meantime, thesolenoid valve (7 a) disposed on the first sub pipe (23) of thecommunicating pipe (21), the outside expanding valve (26), the solenoidvalve (7 g) in the refrigerating unit (1C) and the solenoid valve (7 a)in the freezing unit (1D) are closed.

[0090] In this state, the refrigerant discharged from the first invertercompressor (2B) and the second inverter compressor (2C) flows into theoutside heat exchanger (4) from the first 4-way switch valve (3A) viathe outside gas pipe (9), and then, is condensed in the outside heatexchanger (4). The condensed liquid refrigerant flows in the liquid pipe(10) and the second connecting liquid pipe (12) via the receiver (14),and then, is expanded by the inside expanding valve (42), and finally,is evaporated in the inside heat exchanger (41). The evaporated gaseousrefrigerant flows into the suction pipe (6 c) of the second invertercompressor (2C) from the connecting gas pipe (17) via the first 4-wayswitch valve (3A) and the second 4-way switch valve (3B), and then,returns to the first inverter compressor (2B) and the second invertercompressor (2C). The inside of a room, i.e., the inside of a store iscooled by repeating the above-described circulation of the refrigerant.

[0091] During this cooling operation, the compressors (2B) and (2C) arecontrolled as illustrated in FIG. 3. This control is relevant to twojudgements, as follows: in step ST11, it is judged whether or not afirst condition is satisfied where an inside temperature Tr, which isdetected by the inside temperature sensor (73), is higher than atemperature obtained by adding 3° C. to a setting temperature Tset; andin step ST12, it is judged whether or not a second condition issatisfied where the inside temperature Tr is lower than the settingtemperature Tset.

[0092] If the first condition in step ST11 is satisfied, the controlproceeds to step ST13, in which the performance of the first invertercompressor (2B) or the second inverter compressor (2C) is enhanced, andthen, the control is returned. In contrast, if the first condition instep ST11 is not satisfied but the second condition in step ST12 issatisfied, the control proceeds to step ST14, in which the performanceof the first inverter compressor (2B) or the second inverter compressor(2C) is degraded, and then, the control is returned. Furthermore, unlessthe second condition in step ST12 is satisfied, it is found that thecurrent performance of the compressor is sufficient. Therefore, thecontrol is returned, and then, the above-described processing isrepeated.

[0093] In the present cooling operation, the capacity of the compressoris controlled in steps ST13 and ST14, as follows: namely, as illustratedin FIG. 4, in the above-described control of increasing the capacity ofthe compressor, the capacity of one of the inverter compressors (here,the first inverter compressor (2B)) is first increased from zero in astop state up to a lowest capacity (see a point A), and then, the otherinverter compressor (here, the second inverter compressor (2C)) isdriven from the stop state to be increased in its capacity whilemaintaining the first inverter compressor (2B) at the lowest capacity.Thereafter, when a load is further increased, the capacity of the firstinverter compressor (2B) is increased while maintaining the secondinverter compressor (2C) at a highest capacity (see a point B). To thecontrary, in the control of decreasing the capacity of the compressor,the control is performed in accordance with procedures reverse to thosein the above-described increasing control. Hereinafter, theabove-described control of the capacity of the compressor, that is, thecontrol of the capacity in the case where both of the compressors are ofan inverter type, is referred to as “a first capacity control”.

[0094] Incidentally, the opening degree of the inside expanding valve(42) is controlled by overheating based on the temperatures detected bythe inside heat exchange temperature sensor (71) and the gas temperaturesensor (72).

Cooling Operation in Case of Breakdown of Compressor

[0095] In the present refrigeration apparatus (1), if either one of thefirst inverter compressor (2B) and the second inverter compressor (2C)is broken down during the above-described cooling operation, thenon-inverter compressor (2A) is driven in place of the brokencompressor, so that the cooling operation can be continued.

[0096] For example, if the first inverter compressor (2B) is broken downduring the cooling operation, the controller (80) detects the breakdown,and then, stops the operation of the compressor (2B) while starts thenon-inverter compressor (2A), which has not be operated. That is to say,the controller (80) actuates the non-inverter compressor (2A) in placeof the broken compressor (2B). Consequently, the refrigerant circulates,as illustrated in FIG. 5. In other words, a circulating operation isperformed such that the refrigerant discharged from the non-invertercompressor (2A) and the second inverter compressor (2C) is condensed inthe outside heat exchanger (4), is expanded by the inside expandingvalve (42), is evaporated in the inside heat exchanger (41), andfinally, returns to the non-inverter compressor (2A) and the secondinverter compressor (2C).

[0097] In the present operation, the capacity of the compressor iscontrolled, as follows: namely, as illustrated in FIG. 6, when a load issmall, the inverter compressor (the second inverter compressor (2C) inthe present operation) is first driven in the state in which thenon-inverter compressor (2A) is inoperative (see a point A), so that thecapacity is increased. If the load is further increased after thecapacity of the second inverter compressor (2C) is increased to reach agreatest capacity (see a point B), the non-inverter compressor (2A) isdriven, and at the same time, the second inverter compressor (2C) isdecreased down to a smallest capacity (see a point C). Thereafter, ifthe load is further increased, the capacity of the second invertercompressor (2C) is increased. To the contrary, in the control ofdecreasing the capacity of the compressor, the control is performed inaccordance with procedures reverse to those in the above-describedincreasing control. Hereinafter, the above-described control of thecapacity of the compressor, that is, the control of the capacity in thecase where either one of the compressors is of a non-inverter type whilethe other compressor is of an inverter type, is referred to as “a secondcapacity control”.

[0098] Furthermore, even if the second inverter compressor (2C) isaccidentally broken down during the cooling operation, the coolingoperation can be continued in the same manner as described above.

[0099] As described above, according to the present refrigerationapparatus (1), even if one of the compressors is broken down during thecooling operation, the cooling operation can be continued as it iswithout stopping the cooling operation and inducing any insufficientcooling performance.

Freezing Operation

[0100] In a freezing operation, the refrigerating unit (1C) and thefreezing unit (1D) are actuated to perform only the cooling operation.During the freezing operation, the non-inverter compressor (2A) and thefirst inverter compressor (2B) constitute the compressor mechanism (2D)of the first system while the second inverter compressor (2C)constitutes the compressor mechanism (2E) of the second system, asillustrated in FIG. 7, and only the non-inverter compressor (2A) and thefirst inverter compressor (2B) constituting the compressor mechanism(2D) of the first system are driven, and further, the booster compressor(53) also is driven.

[0101] As indicated by a solid line in FIG. 7, the first 4-way switchvalve (3A) is switched to the first state. The solenoid valve (7 g) inthe refrigerating unit (1C) and the solenoid valve (7 a) in the freezingunit (1D) are opened. In the meantime, the two solenoid valves (7 a) and(7 b) disposed on the communicating pipe (21), the outside expandingvalve (26) and the inside expanding valve (42) are closed.

[0102] In this state, the refrigerant discharged from the non-invertercompressor (2A) and the first inverter compressor (2B) flows into theoutside heat exchanger (4) from the first 4-way switch valve (3A) viathe outside gas pipe (9), and then, is condensed in the outside heatexchanger (4). The condensed liquid refrigerant flows in the liquid pipe(10) and the first connecting liquid pipe (11) via the receiver (14). Apart of the refrigerant is evaporated in the refrigerating heatexchanger (45) via the refrigerating expanding valve (46).

[0103] In the meantime, the residual liquid refrigerant flowing in thefirst connecting liquid pipe (11) flows in the branch liquid pipe (13),and then, is evaporated in the freezing heat exchanger (51) via thefreezing expanding valve (52). The gaseous refrigerant evaporated in thefreezing heat exchanger (51) is sucked to and compressed by the boostercompressor (53), and then, is discharged to the branch gas pipe (16).

[0104] The gaseous refrigerant evaporated in the refrigerating heatexchanger (45) and the gaseous refrigerant discharged from the boostercompressor (53) are converged together in the low pressure gas pipe(15), and then, return to the non-inverter compressor (2A) and the firstinverter compressor (2B). The inside of the refrigerating show case andthe inside of the freezing show case are cooled by repeating theabove-described circulation of the refrigerant.

[0105] In this manner, since the refrigerant flowing out of the freezingheat exchanger (51) is sucked to the booster compressor (53), thepressure of the refrigerant in the freezing heat exchanger (51) becomeslower than that in the refrigerating heat exchanger (45). Consequently,for example, the temperature (i.e., the evaporation temperature) of therefrigerant in the freezing heat exchanger (51) becomes −40° C.; incontrast, the temperature (i.e., the evaporation temperature) of therefrigerant in the refrigerating heat exchanger (45) becomes −10° C.That is to say, the cooling operation is performed at different coolingtemperatures.

[0106] During this freezing operation, the capacity of the compressor iscontrolled as illustrated in FIG. 8. This control is relevant to twojudgements, as follows: in step ST21, it is judged whether or not afirst condition is satisfied where the pressure LP of a low pressurerefrigerant, which is detected by the low pressure sensor (65) or (66),is higher than 392 kPa; and in step ST22, it is judged whether or not asecond condition is satisfied where the pressure LP of the low pressurerefrigerant is lower than 245 kPa.

[0107] If it is judged in step ST21 that the first condition issatisfied, the control proceeds to step ST23, in which the performanceof the first inverter compressor (2B) or the non-inverter compressor(2A) is enhanced, and then, the control is returned. In contrast, if itis judged in step ST21 that the first condition is not satisfied but itis judged in step ST22 that the second condition is satisfied, thecontrol proceeds to step ST24, in which the performance of the firstinverter compressor (2B) or the non-inverter compressor (2A) isdegraded, and then, the control is returned. Furthermore, if it isjudged in step ST22 that the second condition is not satisfied, it isfound that the current performance of the compressor is sufficient.Therefore, the control is returned, and then, the above-describedprocessing is repeated.

[0108] In the present operation, since the non-inverter compressor (2A)and the first inverter compressor (2B) carry out the operation, theabove-described second capacity control is performed in steps ST23 andST24 (see FIG. 6).

[0109] In addition, the opening degrees of the refrigerating expandingvalve (46) and the freezing expanding valve (52) are controlled byoverheating by the use of the thermosensitive cylinder. Hereinafter, thesame goes for each of the operations.

Freezing Operation in Case of Breakdown of Compressor

[0110] In the present refrigeration apparatus (1), if either one of thenon-inverter compressor (2A) and the first inverter compressor (2B) isbroken down during the above-described freezing operation, the secondinverter compressor (2C) is driven, and further, the solenoid valve (7a) of the first sub pipe (23) is opened, thereby continuing the freezingoperation.

[0111] Specifically, if the first inverter compressor (2B) is brokendown during the freezing operation, the controller (80) detects thebreakdown, and then, stops the operation of the compressor (2B) whilestarts the second inverter compressor (2C), which has not be operated,and further, opens the solenoid valve (7 a). Consequently, therefrigerant circulates as illustrated in FIG. 9. In other words, acirculating operation is performed such that the refrigerant dischargedfrom the non-inverter compressor (2A) and the second inverter compressor(2C) is condensed in the outside heat exchanger (4), is expanded by therefrigerating expanding valve (46) and the freezing expanding valve(52), is evaporated in the refrigerating heat exchanger (45) and thefreezing heat exchanger (51), and finally, returns to the non-invertercompressor (2A) and the second inverter compressor (2C).

[0112] The non-inverter compressor (2A) and the second invertercompressor (2C) are controlled in accordance with the above-describedsecond capacity control (see FIG. 6).

[0113] In contrast, if the non-inverter compressor (2A) is broken downduring the freezing operation, the controller (80) detects thebreakdown, and then, stops the operation of the compressor (2A) whilestarts the second inverter compressor (2C), which has not been operated,and further, opens the solenoid valve (7 a). In this case, a circulatingoperation is performed such that the refrigerant discharged from thefirst inverter compressor (2B) and the second inverter compressor (2C)is condensed in the outside heat exchanger (4), is expanded by therefrigerating expanding valve (46) and the freezing expanding valve(52), is evaporated in the refrigerating heat exchanger (45) and thefreezing heat exchanger (51), and finally, returns to the first invertercompressor (2B) and the second inverter compressor (2C).

[0114] The first inverter compressor (2B) and the second invertercompressor (2C) are controlled in accordance with the above-describedfirst capacity control (see FIG. 4).

[0115] As a consequence, even if one of the compressors is broken downduring the freezing operation, the freezing operation can be continuedas it is without stopping the freezing operation and inducing anyinsufficient freezing performance.

Cooling/Freezing Operation

[0116] In a cooling/freezing operation, the cooling operation in theinside unit (1B) is performed, and further, the freezing operation inthe refrigerating unit (1C) and the freezing unit (1D) are performed atthe same time. During the cooling/freezing operation, the non-invertercompressor (2A) and the first inverter compressor (2B) constitute thecompressor mechanism (2D) of the first system while the second invertercompressor (2C) constitutes the compressor mechanism (2E) of the secondsystem, as illustrated in FIG. 10. The non-inverter compressor (2A), thefirst inverter compressor (2B) and the second inverter compressor (2C)are driven, and further, the booster compressor (53) also is driven.

[0117] As indicated by a solid line in FIG. 10, the first 4-way switchvalve (3A) and the second 4-way switch valve (3B) are switched to thefirst state, respectively. The solenoid valve (7 g) in the refrigeratingunit (1C) and the solenoid valve (7 a) in the freezing unit (1D) areopened. In the meantime, the two solenoid valves (7 a) and (7 b)disposed on the communicating pipe (21) and the outside expanding valve(26) are closed.

[0118] In this state, the refrigerants discharged from the non-invertercompressor (2A), the first inverter compressor (2B) and the secondinverter compressor (2C) are converged together in the high pressure gaspipe (8), and then, the converged refrigerant is condensed in theoutside heat exchanger (4) from the first 4-way switch valve (3A) viathe outside gas pipe (9). The condensed liquid refrigerant flows in theliquid pipe (10), and then, is divided to the first connecting liquidpipe (11) and the second connecting liquid pipe (12) via the receiver(14).

[0119] The liquid refrigerant flowing in the second connecting liquidpipe (12) is expanded in the inside expanding valve (42), and then, isevaporated in the inside heat exchanger (41). The evaporated gaseousrefrigerant flows in the suction pipe (6 c) from the connecting gas pipe(17) via the first 4-way switch valve (3A) and the second 4-way switchvalve (3B), and then, returns to the second inverter compressor (2C).

[0120] In the meantime, a part of the liquid refrigerant flowing in thefirst connecting liquid pipe (11) is expanded in the refrigeratingexpanding valve (46), and then, is evaporated in the refrigerating heatexchanger (45). Furthermore, the residual liquid refrigerant flowing inthe first connecting liquid pipe (11) flows in the branch liquid pipe(13), is expanded in the freezing expanding valve (52), and then, isevaporated in the freezing heat exchanger (51). The gaseous refrigerantevaporated in the freezing heat exchanger (51) is sucked to andcompressed by the booster compressor (53), and finally, is discharged tothe branch gas pipe (16).

[0121] The gaseous refrigerant evaporated in the refrigerating heatexchanger (45) and the gaseous refrigerant discharged from the boostercompressor (53) are converged together in the low pressure gas pipe(15), and then, return to the non-inverter compressor (2A) and the firstinverter compressor (2B).

[0122] The inside of the room, i.e., the inside of the store, the insideof the refrigerating show case and the inside of the freezing show caseare cooled by repeating the above-described circulation of therefrigerant.

[0123] Subsequently, explanation will be made on a freezing cycle duringthe cooling/freezing operation in reference to FIG. 11.

[0124] The refrigerant sucked by the second inverter compressor (2C) iscompressed up to a point A. Furthermore, the refrigerant is compressedup to a point B by the non-inverter compressor (2A) and the firstinverter compressor (2B). The refrigerant at the point A and therefrigerant at the point B are converged together, to be thus condensedinto a refrigerant at a point C. A part of the refrigerant at the pointC is reduced in pressure down to a point D by the inside expanding valve(42), and then, is evaporated at, for example, +5° C., and thus, issucked at a point E by the second inverter compressor (2C).

[0125] Moreover, a part of the refrigerant at the point C is reduced inpressure down to a point F by the refrigerating expanding valve (46),and then, is evaporated at, for example, −10° C., and thus, is sucked ata point G by the non-inverter compressor (2A) and the first invertercompressor (2B).

[0126] Additionally, another part of the refrigerant at the point C isreduced in pressure down to a point H by the freezing expanding valve(52), and then, is evaporated at, for example, −40° C., and thus, issucked at a point I by the booster compressor (53). The refrigerantcompressed up to a point J by the booster compressor (53) is sucked atthe point G by the non-inverter compressor (2A) and the first invertercompressor (2B).

[0127] In this manner, the refrigerant in the refrigerant circuit (1E)is compressed by the compressor mechanism (2D) of the first system, thecompressor mechanism (2E) of the second system and the boostercompressor (53), and therefore, is evaporated at the three kinds, intotal, of evaporation temperatures.

Cooling/Freezing Operation in Case of Breakdown of Compressor

[0128] In the present refrigeration apparatus (1), if either one of thenon-inverter compressor (2A) and the first inverter compressor (2B) isbroken down during the above-described cooling/freezing operation, thesolenoid valve (7 a) of the first sub pipe (23) is opened, therebycontinuing the cooling/freezing operation.

[0129] For example, if the first inverter compressor (2B) is broken downduring the cooling/freezing operation, the controller (80) detects thebreakdown, and then, stops the operation of the compressor (2B) whileopens the solenoid valve (7 a). Consequently, the refrigerant circulatesas illustrated in FIG. 12.

[0130] In other words, the refrigerant discharged from the non-invertercompressor (2A) and the second inverter compressor (2C) is condensed inthe outside heat exchanger (4), and then, is diverged to flow into theinside unit (1B), the refrigerating unit (1C) and the freezing unit(1D). In the same manner as in the above-described cooling/freezingoperation, the refrigerant flowing into the refrigerating unit (1C) andthe freezing unit (1D) is expanded by the refrigerating expanding valve(46) and the freezing expanding valve (52), respectively, and then, isevaporated in the refrigerating heat exchanger (45) and the freezingheat exchanger (51), respectively. In the meantime, the refrigerantflowing into the inside unit (1B) is expanded by the inside expandingvalve (42), and then, is evaporated in the inside heat exchanger (41).

[0131] Here, since the solenoid valve (7 a) is opened, the suction sideof the non-inverter compressor (2A) and the suction side of the secondinverter compressor (2C) communicate with each other via the first subpipe (23). Therefore, in the present operation, the suction pressure ofthe non-inverter compressor (2A) and the suction pressure of the secondinverter compressor (2C) become equal to each other. As a result, unlikethe cooling/freezing operation in the case where no compressor is brokendown, the pressure of the refrigerant in the inside heat exchanger (41)becomes equal to that of the refrigerant in the refrigerating heatexchanger (45). Consequently, the evaporation temperature of therefrigerant in the inside heat exchanger (41) becomes equal to that ofthe refrigerant in the refrigerating heat exchanger (45), so that thecooling temperature of the inside heat exchanger (41) becomes lower thanthat before the breakdown of the compressor.

[0132] The number of operating compressors is reduced from three to twocaused by the breakdown of the first inverter compressor (2B), therebyreducing the entire quantity of the refrigerant circulating in therefrigerant circuit (1E). However, since the evaporation temperature ofthe refrigerant in the inside heat exchanger (41) is decreased in thepresent operation, it is sufficient that the circulating refrigerantquantity required for maintaining the cooling performance of the insideheat exchanger (41) is small. Thus, the cooling/freezing operation canbe continued without degrading the cooling performance of each of therefrigerating heat exchanger (45) and the freezing heat exchanger (51)and the cooling performance of the inside heat exchanger (41).

[0133] In the present operation, control is carried out as illustratedin FIG. 13. That is to say, first, it is judged in step ST51 whether ornot the non-inverter compressor (2A) or the first inverter compressor(2B) is broken down. If the judgement result is YES, the controlproceeds to step ST52, in which the solenoid valve (7 a) is opened.Subsequently, it is judged in step ST53 whether or not the pressure LPof the low pressure refrigerant is higher than 392 kPa. If the judgementresult is YES, the performance of the compressor is enhanced in ST55,and then, the control is returned. In contrast, if the judgement resultin step ST53 is NO, the control proceeds to step ST54, in which it isjudged whether or not the pressure LP of the low pressure refrigerant islower than 245 kPa. If the judgement result is YES, the control proceedsto step ST56, in which the performance of the compressor is degraded,and then, the control is returned. In contrast, if the judgement resultin step ST54 is NO, the control is returned as it is.

[0134] In the present refrigeration apparatus (1), if the secondinverter compressor (2C) is broken down during the above-describedcooling/freezing operation, the solenoid valve (7 b) of the second subpipe (24) is appropriately opened, thereby continuing thecooling/freezing operation.

[0135] Specifically, control is carried out as illustrated in FIG. 14.That is to say, first, it is judged in step ST31 whether or not thesecond inverter compressor (2C) is broken down. If the judgement resultis YES, the control proceeds to step ST32. In step ST32, it is judgedwhether or not the solenoid valve (7 b) of the second sub pipe (24) isopened. If the judgement result in step ST32 is NO, the control proceedsto step ST33, in which it is judged whether or not the pressure LP ofthe low pressure refrigerant is higher than 392 kPa. If the judgementresult in step ST33 is NO, the control proceeds to step ST34, in whichit is judged whether or not the pressure LP of the low pressurerefrigerant is lower than 245 kPa. If the judgement result in step ST34is NO, the control is returned.

[0136] If the judgement result in step ST32 is YES, it is judged in stepST36 whether or not a condition of (the inside temperature Tr−thesetting temperature Tset)<0° C. is satisfied. If the judgement result isYES, it is judged that it is unnecessary to cool the inside of the storesince the inside temperature is lower than the setting temperature, andthen, the control proceeds to step ST42, in which the solenoid valve (7b) is closed, and further, the inside expanding valve (42) is closed,and finally, the control is returned. In contrast, if the judgementresult in step ST36 is NO, the control proceeds to step ST37.

[0137] In step ST37, it is judged whether or not a condition of (theinside temperature Tr−the setting temperature Tset)>3° C. or thepressure LP of the low pressure refrigerant>392 kPa is satisfied. If thejudgement result is YES, the control proceeds to step ST38, in which theperformance of the compressor is enhanced, and finally, the control isreturned. In contrast, if the judgement result in step ST37 is NO, thecontrol proceeds to step ST39, in which it is judged whether or not acondition of the highest performance of the compressor and the pressureLP of the low pressure refrigerant>392 kPa is satisfied. If thejudgement result in step ST39 is YES, the control proceeds to step ST42;in contrast, if the judgement result in step ST39 is NO, the control isreturned.

[0138] In the meantime, if the judgement result in step ST33 is YES, thecontrol proceeds to step ST40, in which the performance of thecompressor is enhanced, and finally, the control is returned. Incontrast, if the judgement result in step ST34 is YES, the controlproceeds to step ST41, in which the solenoid valve (7 b) is opened, andthen, the control is returned.

[0139] As described above, according to the present refrigerationapparatus (1), even if one of the compressors is broken down during thecooling/freezing operation, the cooling/freezing operation can becontinued as it is without stopping the cooling/freezing operation andinducing insufficient cooling and freezing performances.

Warming Operation

[0140] In a warming operation, the inside unit (1B) and the floorwarming circuit (35) are actuated to perform only a warming operation.During the warming operation, the non-inverter compressor (2A)constitutes the compressor mechanism (2D) of the first system while thefirst inverter compressor (2B) and the second inverter compressor (2C)constitute the compressor mechanism (2E) of the second system, asillustrated in FIG. 15, and only the first inverter compressor (2B) andthe second inverter compressor (2C) constituting the compressormechanism (2E) of the second system are driven.

[0141] As indicated by a solid line in FIG. 15, the first 4-way switchvalve (3A) is switched to the second state, and further, the second4-way switch valve (3B) is switched to the first state. The solenoidvalve (7 b) disposed on the second sub pipe (24) of the communicatingpipe (21) is opened. In the meantime, the solenoid valve (7 a) disposedon the first sub pipe (23) of the communicating pipe (21), the solenoidvalve (7 g) in the refrigerating unit (1C) and the solenoid valve (7 a)in the freezing unit (1D) are closed.

[0142] In this state, the refrigerant discharged from the first invertercompressor (2B) and the second inverter compressor (2C) is condensed inthe inside heat exchanger (41) from the first 4-way switch valve (3A)via the connecting gas pipe (17). The condensed liquid refrigerant flowsin the second connecting liquid pipe (12) and the floor warming circuit(35), and further, flows into the receiver (14) via the floor warmingheat exchanger (36). Thereafter, the liquid refrigerant is evaporated inthe outside heat exchanger (4) via the outside expanding valve (26) ofthe auxiliary liquid pipe (25). The evaporated gaseous refrigerant flowsinto the suction pipe (6 c) of the second inverter compressor (2C) viathe first 4-way switch valve (3A) and the second 4-way switch valve(3B), and then, returns to the first inverter compressor (2B) and thesecond inverter compressor (2C). The inside of the room, i.e., theinside of the store and the floor are warmed by repeating theabove-described circulation of the refrigerant.

[0143] During this warming operation, the capacity of the compressor iscontrolled as illustrated in FIG. 16. This control is relevant to twojudgements, as follows: in step ST61, it is judged whether or not afirst condition of (the setting temperature Tset−the inside temperatureTr)>3° C. is satisfied; and in step ST62, it is judged whether or not asecond condition of (the setting temperature Tset−the inside temperatureTr)<0° C. is satisfied.

[0144] If it is judged in step ST61 that the first condition issatisfied, the control proceeds to step ST63, in which the performanceof the first inverter compressor (2B) or the second inverter compressor(2C) is enhanced, and then, the control is returned. In contrast, if itis judged in step ST61 that the first condition is not satisfied but itis judged in step ST62 that the second condition is satisfied, thecontrol proceeds to step ST64, in which the performance of the firstinverter compressor (2B) or the second inverter compressor (2C) isdegraded, and then, the control is returned. Furthermore, if it isjudged in step ST12 that the second condition is not satisfied, it isfound that the current performance of the compressor is sufficient.Therefore, the control is returned, and then, the above-describedprocessing is repeated. The capacity of the compressor is increased ordecreased in accordance with the above-described first capacity control(see FIG. 4).

[0145] The opening degree of the outside expanding valve (26) iscontrolled by overheating based on pressure equivalent saturationtemperatures detected by the low pressure sensors (65) and (66) andtemperatures detected by the suction temperature sensors (67) and (68).The opening degree of the inside expanding valve (42) is controlled byovercooling based on temperatures detected by the inside heat exchangetemperature sensor (71) and the liquid temperature sensor (76).

Warming Operation in Case of Breakdown of Compressor

[0146] In the present refrigeration apparatus (1), if either one of thefirst inverter compressor (2B) and the second inverter compressor (2C)is broken down during the above-described warming operation, thenon-inverter compressor (2A) is driven in place of the brokencompressor, so that the warming operation can be continued.

[0147] For example, if the first inverter compressor (2B) is broken downduring the warming operation, the controller (80) detects the breakdown,and then, stops the operation of the compressor (2B) while starts thenon-inverter compressor (2A), which has not been operated. Consequently,the refrigerant circulates as illustrated in FIG. 17. In other words, acirculating operation is performed such that the refrigerant dischargedfrom the non-inverter compressor (2A) and the second inverter compressor(2C) is condensed in the inside heat exchanger (41) and the floorwarming heat exchanger (36), is expanded by the outside expanding valve(26), is evaporated in the outside heat exchanger (4), and finally,returns to the non-inverter compressor (2A) and the second invertercompressor (2C).

[0148] The capacity of the compressor is increased or decreased in thepresent operation in accordance with the above-described second capacitycontrol (see FIG. 6).

[0149] Incidentally, even if the second inverter compressor (2C) isaccidentally broken down, the warming operation can be continued in thesame manner as described above by actuating the non-inverter compressor(2A) in place of the second inverter compressor (2C).

[0150] As described above, according to the present refrigerationapparatus (1), even if one of the compressors is broken down during thewarming operation, the warming operation can be continued as it iswithout stopping the warming operation and inducing any insufficientwarming performance.

Warming/Freezing Operation

[0151] In a warming/freezing operation, the non-inverter compressor (2A)and the first inverter compressor (2B) constitute the compressormechanism (2D) of the first system while the second inverter compressor(2C) constitutes the compressor mechanism (2E) of the second system, asillustrated in FIG. 18. The non-inverter compressor (2A) and the firstinverter compressor (2B) are driven, and further, the booster compressor(53) also is driven. The second inverter compressor (2C) is inoperative.

[0152] As indicated by a solid line in FIG. 18, the first 4-way switchvalve (3A) is switched to the second state, and further, the second4-way switch valve (3B) is switched to the second state. The solenoidvalve (7 g) in the refrigerating unit (1C) and the solenoid valve (7 a)in the freezing unit (1D) are opened. In the meantime, the two solenoidvalves (7 a) and (7 b) disposed on the communicating pipe (21) and theoutside expanding valve (26) are closed.

[0153] A part of the refrigerant discharged from the non-invertercompressor (2A) and the first inverter compressor (2B) is condensed inthe inside heat exchanger (41). The condensed liquid refrigerant flowsin the floor warming circuit (35), and further, flows into the liquidpipe (10) via the floor warming heat exchanger (36).

[0154] In the meantime, the residual refrigerant discharged from thenon-inverter compressor (2A) and the first inverter compressor (2B)flows in the outside gas pipe (9) from the auxiliary gas pipe (19) viathe second 4-way switch valve (3B) and the first 4-way switch valve(3A), and then, is condensed in the outside heat exchanger (4). Thecondensed liquid refrigerant flows in the liquid pipe (10), and then, isconverged with the liquid refrigerant from the floor warming circuit(35). Thereafter, the liquid refrigerant flows into the receiver (14),and then, in the first connecting liquid pipe (11).

[0155] A part of the liquid refrigerant flowing in the first connectingliquid pipe (11) is evaporated in the refrigerating heat exchanger (45).Furthermore, the residual liquid refrigerant flowing in the firstconnecting liquid pipe (11) is evaporated in the freezing heat exchanger(51). The gaseous refrigerant evaporated in the refrigerating heatexchanger (45) and the gaseous refrigerant discharged from the boostercompressor (53) are converged together in the low pressure gas pipe(15), and then, return to the non-inverter compressor (2A) and the firstinverter compressor (2B). By repeating the above-described circulationof the refrigerant, the inside of the room, i.e., the inside of thestore and the floor are warmed, and at the same time, the inside of therefrigerating show case and the inside of the freezing show case arecooled.

[0156] During this warming/freezing operation, the capacity of thecompressor and the air quantity of the outside fan (4F) are controlledas illustrated in FIG. 19. This control is relevant to four judgements,as described below.

[0157] That is to say, in step ST81, it is judged whether or not a firstcondition of (the setting temperature Tset−the inside temperature Tr)>3°C. and the pressure LP of the low pressure refrigerant>392 kPa issatisfied. In step ST82, it is judged whether or not a second conditionof (the setting temperature Tset−the inside temperature Tr)>3° C. andthe pressure LP of the low pressure refrigerant<245 kPa is satisfied. Instep ST83, it is judged whether or not a third condition of (the settingtemperature Tset−the inside temperature Tr)<0° C. and the pressure LP ofthe low pressure refrigerant>392 kPa is satisfied. In step ST84, it isjudged whether or not a fourth condition of (the setting temperatureTset−the inside temperature Tr)<0° C. and the pressure LP of the lowpressure refrigerant<245 kPa is satisfied.

[0158] If it is judged in step ST81 that the first condition issatisfied, the control proceeds to step ST85, in which the performanceof the first inverter compressor (2B) or the non-inverter compressor(2A) is enhanced, and then, the control is returned. In contrast, if itis judged in step ST81 that the first condition is not satisfied but itis judged in step ST82 that the second condition is satisfied, thecontrol proceeds to step ST86, in which the air quantity of the outsidefan (4F) is decreased, and then, the control is returned. In otherwords, since the warming performance is slightly insufficient, thecondensed heat in the outside heat exchanger (4) is applied to theinside heat exchanger (41). Furthermore, if it is judged in step ST82that the second condition is not satisfied but it is judged in step ST83that the third condition is satisfied, the control proceeds to stepST87, in which the air quantity of the outside fan (4F) is increased,and then, the control is returned. In other words, since the warmingperformance is slightly excessive, the condensed heat in the inside heatexchanger (41) is applied to the outside heat exchanger (4). Moreover,if it is judged in step ST83 that the third condition is not satisfiedbut it is judged in step ST84 that the fourth condition is satisfied,the control proceeds to step ST88, in which the performance of the firstinverter compressor (2B) or the non-inverter compressor (2A) isdegraded, and then, the control is returned. Additionally, if it isjudged in step ST84 that the fourth condition is satisfied, since thecurrent performance of the compressor is sufficient, the control isreturned. The above-described processing is repeated. The capacity ofthe compressor is controlled to be increased or decreased in accordancewith the second capacity control (see FIG. 6).

Warming/Freezing Operation in Case of Breakdown of Compressor

[0159] In the present refrigeration apparatus (1), if the non-invertercompressor (2A) or the first inverter compressor (2B) is broken downduring the above-described warming/freezing operation, the secondinverter compressor (2C) is driven in place of the broken compressor,and further, the solenoid valve (7 a) of the first sub pipe (23) isopened, thereby continuing the warming/freezing operation.

[0160] For example, if the first inverter compressor (2B) is broken downduring the warming/freezing operation, the controller (80) detects thebreakdown, and then, stops the operation of the compressor (2B) whilestarts the second inverter compressor (2C), which has not been operated,and further, opens the solenoid valve (7 a). Consequently, therefrigerant circulates as illustrated in FIG. 20. In other words, a partof the refrigerant discharged from the non-inverter compressor (2A) andthe second inverter compressor (2C) is condensed in the inside heatexchanger (41) and the floor warming heat exchanger (36). In themeantime, the residual refrigerant discharged from the non-invertercompressor (2A) and the second inverter compressor (2C) is condensed inthe outside heat exchanger (4). The condensed liquid refrigerant isconverged with the refrigerant from the floor warming heat exchanger(36), and then, flows into the receiver (14). The refrigerant from thereceiver (14) is evaporated in the refrigerating heat exchanger (45) andthe freezing heat exchanger (51), and then, returns to the non-invertercompressor (2A) and the second inverter compressor (2C). The capacity ofeach of the non-inverter compressor (2A) and the second invertercompressor (2C) is controlled in accordance with the second capacitycontrol (see FIG. 6).

[0161] Incidentally, even if the non-inverter compressor (2A) isaccidentally broken down, the warming/freezing operation can becontinued in the same manner as described above by actuating the secondinverter compressor (2C) in place of the non-inverter compressor (2A).

[0162] As described above, according to the present refrigerationapparatus (1), even if one of the compressors is broken down during thewarming/freezing operation, the warming/freezing operation can becontinued as it is without stopping the warming/freezing operation andinducing insufficient warming performance and insufficient freezingperformance.

Other Preferred Embodiments

[0163] The refrigeration apparatus according to the present invention isnot limited to a type comprising the three compressors, and therefore,it may comprise four or more compressors.

[0164] Although “the first compressor”, “the second compressor” and “thethird compressor” according to the present invention may correspond tothe non-inverter compressor (2A), the first inverter compressor (2B) andthe second inverter compressor (2C) in the above-described preferredembodiment, respectively, the corresponding relationship may bedifferent: for example, the non-inverter compressor (2A) or the secondinverter compressor (2C) corresponds to “the second compressor”according to the present invention. That is to say, their correspondingrelationships are not limited in particular.

AVAILABILITY OF INDUSTRIAL UTILIZATION

[0165] As described above, the refrigeration apparatus according to thepresent invention is usable in a refrigeration apparatus which canfreely perform both of the air-conditioning and freezing operations.

1. A refrigeration apparatus comprising: a refrigerant circuit (1E)including first, second and third compressors (2A, 2B, 2C) connected inparallel each other, a heat source side heat exchanger (4), anair-conditioning heat exchanger (41) for air-conditioning the inside ofa room, a cooling heat exchanger (45, 51) for cooling the inside of acold store, and first and second expanding mechanisms (42, 46, 52) forexpanding a refrigerant; and breakdown detecting means (80) fordetecting the breakdown of at least the second compressor (2B); therefrigeration apparatus being capable of freely performing at least acooling operation and a freezing operation, wherein the coolingoperation is performed by actuating the second compressor (2B) and thethird compressor (2C), the cooling operation being achieved bycondensing a refrigerant discharged from the second compressor (2B) andthe third compressor (2C) by means of the heat source side heatexchanger (4), expanding it by the first expanding mechanism (42),evaporating it by the air-conditioning heat exchanger (41), andreturning it to the second compressor (2B) and the third compressor(2C), and further, the freezing operation is performed by actuating thefirst compressor (2A) and the second compressor (2B), the freezingoperation being achieved by condensing a refrigerant discharged from thefirst compressor (2A) and the second compressor (2B) by means of theheat source side heat exchanger (4), expanding it by the secondexpanding mechanism (46, 52), evaporating it by the cooling heatexchanger (45, 51), and returning it to the first compressor (2A) andthe second compressor (2B); and the cooling operation being continued byactuating the first compressor (2A) in place of the second compressor(2B) if the breakdown of the second compressor (2B) is detected duringthe cooling operation.
 2. A refrigeration apparatus comprising: arefrigerant circuit (1E) including first, second and third compressors(2A, 2B, 2C) connected in parallel each other, a heat source side heatexchanger (4), an air-conditioning heat exchanger (41) forair-conditioning the inside of a room, a cooling heat exchanger (45, 51)for cooling the inside of a cold store, and first and second expandingmechanisms (42, 46, 52) for expanding a refrigerant; and breakdowndetecting means (80) for detecting the breakdown of at least the secondcompressor (2B); the refrigeration apparatus being capable of freelyperforming at least a freezing operation and a cooling/freezingoperation, wherein the freezing operation is performed by actuating thefirst compressor (2A) and the second compressor (2B), the freezingoperation being achieved by condensing a refrigerant discharged from thefirst compressor (2A) and the second compressor (2B) by means of theheat source side heat exchanger (4), expanding it by the secondexpanding mechanism (46, 52), evaporating it by the cooling heatexchanger (45, 51), and returning it to the first compressor (2A) andthe second compressor (2B), and further, the cooling/freezing operationis performed by actuating the first compressor (2A), the secondcompressor (2B) and the third compressor (2C), the cooling/freezingoperation being achieved by condensing a refrigerant discharged from thefirst compressor (2A), the second compressor (2B) and the thirdcompressor (2C) by means of the heat source side heat exchanger (4),reducing the pressure of a part of the condensed refrigerant down to afirst low pressure by the first expanding mechanism (42), evaporating itby the air-conditioning heat exchanger (41), and returning it to thethird compressor (2C) while reducing the pressure of the residualcondensed refrigerant down to a second low pressure lower than the firstlow pressure by the second expanding mechanism (46, 52), evaporating itby the cooling heat exchanger (45, 51), and returning it to the firstcompressor (2A) and the second compressor (2B); the refrigerant circuit(1E) further including a refrigerant pipeline (23) for introducing therefrigerant from pipelines on the suction sides of the first compressor(2A) and the second compressor (2B) to a pipeline on the suction side ofthe third compressor (2C), and channel switching means (7 a) disposed onthe refrigerant pipeline (23); and the freezing operation beingcontinued by opening the channel switching means (7 a), and further,actuating the third compressor (2C) in place of the second compressor(2B) if the breakdown of the second compressor (2B) is detected duringthe freezing operation.
 3. A refrigeration apparatus comprising: arefrigerant circuit (1E) including first, second and third compressors(2A, 2B, 2C) connected in parallel each other, a heat source side heatexchanger (4), an air-conditioning heat exchanger (41) forair-conditioning the inside of a room, a cooling heat exchanger (45, 51)for cooling the inside of a cold store, and first and second expandingmechanisms (42, 46, 52) for expanding a refrigerant; and breakdowndetecting means (80) for detecting the breakdown of at least the secondcompressor (2B); the refrigeration apparatus being capable of freelyperforming at least a freezing operation and a cooling/freezingoperation, wherein the freezing operation is performed by actuating thefirst compressor (2A) and the second compressor (2B), the freezingoperation being achieved by condensing a refrigerant discharged from thefirst compressor (2A) and the second compressor (2B) by means of theheat source side heat exchanger (4), expanding it by the secondexpanding mechanism (46, 52), evaporating it by the cooling heatexchanger (45, 51), and returning it to the first compressor (2A) andthe second compressor (2B), and further, the cooling/freezing operationis performed by actuating the first compressor (2A), the secondcompressor (2B) and the third compressor (2C), the cooling/freezingoperation being achieved by condensing a refrigerant discharged from thefirst compressor (2A), the second compressor (2B) and the thirdcompressor (2C) by means of the heat source side heat exchanger (4),reducing the pressure of a part of the condensed refrigerant down to afirst low pressure by the first expanding mechanism (42), evaporating itby the air-conditioning heat exchanger (41), and returning it to thethird compressor (2C) while reducing the pressure of the residualcondensed refrigerant down to a second low pressure lower than the firstlow pressure by the second expanding mechanism (46, 52), evaporating itby the cooling heat exchanger (45, 51), and returning it to the firstcompressor (2A) and the second compressor (2B); the refrigerant circuit(1E) further including a refrigerant pipeline (23) for introducing therefrigerant from pipelines on the suction sides of the first compressor(2A) and the second compressor (2B) to a pipeline on the suction side ofthe third compressor (2C), and channel switching means (7 a) disposed onthe refrigerant pipeline (23); and the cooling/freezing operation beingcontinued by opening the channel switching means (7 a), and further, bycondensing the refrigerant discharged from the first compressor (2A) andthe third compressor (2C) by means of the heat source side heatexchanger (4) on the side of the heat source, reducing the pressure downto a predetermined pressure lower than the first low pressure by thefirst expanding mechanism (42) and the second expanding mechanism (46,52), respectively, evaporating it by the air-conditioning heat exchanger(41) and the cooling heat exchanger (45, 51), and returning it to thefirst compressor (2A) and the third compressor (2C) if the breakdown ofthe second compressor (2B) is detected during the cooling/freezingoperation.
 4. A refrigeration apparatus comprising: a refrigerantcircuit (1E) including first, second and third compressors (2A, 2B, 2C)connected in parallel each other, a heat source side heat exchanger (4),an air-conditioning heat exchanger (41) for air-conditioning the insideof a room, a cooling heat exchanger (45, 51) for cooling the inside of acold store, and first and second expanding mechanisms (42, 46, 52) forexpanding a refrigerant; and breakdown detecting means (80) fordetecting the breakdown of at least the third compressor (2C); therefrigeration apparatus being capable of freely performing at least afreezing operation and a cooling/freezing operation, wherein thefreezing operation is performed by actuating the first compressor (2A)and the second compressor (2B), the freezing operation being achieved bycondensing a refrigerant discharged from the first compressor (2A) andthe second compressor (2B) by means of the heat source side heatexchanger (4), expanding it by the second expanding mechanism (46, 52),evaporating it by the cooling heat exchanger (45, 51), and returning itto the first compressor (2A) and the second compressor (2B), andfurther, the cooling/freezing operation is performed by actuating thefirst compressor (2A), the second compressor (2B) and the thirdcompressor (2C), the cooling/freezing operation being achieved bycondensing a refrigerant discharged from the first compressor (2A), thesecond compressor (2B) and the third compressor (2C) by means of theheat source side heat exchanger (4), reducing the pressure of a part ofthe condensed refrigerant down to a first low pressure by the firstexpanding mechanism (42), evaporating it by the air-conditioning heatexchanger (41), and returning it to the third compressor (2C) whilereducing the pressure of the residual condensed refrigerant down to asecond low pressure lower than the first low pressure by the secondexpanding mechanism (46, 52), evaporating it by the cooling heatexchanger (45, 51), and returning it to the first compressor (2A) andthe second compressor (2B); the refrigerant circuit (1E) furtherincluding a refrigerant pipeline (24) for introducing the refrigerantfrom a pipeline on the suction side of the third compressor (2C) topipelines on the suction sides of the first compressor (2A) and thesecond compressor (2B), and channel switching means (7 b) disposed onthe refrigerant pipeline (24); and the cooling/freezing operation beingcontinued by opening the channel switching means (7 b), and further, bycondensing the refrigerant discharged from the first compressor (2A) andthe second compressor (2B) by means of the heat source side heatexchanger (4), reducing the pressure down to a predetermined pressurelower than the first low pressure by the first expanding mechanism (42)and the second expanding mechanism (46, 52), respectively, evaporatingit by the air-conditioning heat exchanger (41) and the cooling heatexchanger (45, 51), and returning it to the first compressor (2A) andthe second compressor (2B) if the breakdown of the third compressor (2C)is detected during the cooling/freezing operation.
 5. A refrigerationapparatus comprising: a refrigerant circuit (1E) including first, secondand third compressors (2A, 2B, 2C) connected in parallel each other, aheat source side heat exchanger (4), an air-conditioning heat exchanger(41) for air-conditioning the inside of a room, a cooling heat exchanger(45, 51) for cooling the inside of a cold store, and first and secondexpanding mechanisms (42, 46, 52) for expanding a refrigerant; andbreakdown detecting means (80) for detecting the breakdown of at leastthe second compressor (2B); the refrigeration apparatus being capable offreely performing at least a warming operation and a freezing operation,wherein the warming operation is performed by actuating the secondcompressor (2B) and the third compressor (2C), the warming operationbeing achieved by condensing a refrigerant discharged from the secondcompressor (2B) and the third compressor (2C) by means of theair-conditioning heat exchanger (41), expanding it by the firstexpanding mechanism (26), evaporating it by the heat source side heatexchanger (4), and returning it to the second compressor (2B) and thethird compressor (2C), and further, the freezing operation is performedby actuating the first compressor (2A) and the second compressor (2B),the freezing operation being achieved by condensing a refrigerantdischarged from the first compressor (2A) and the second compressor (2B)by means of the heat source side heat exchanger (4), expanding it by thesecond expanding mechanism (46, 52), evaporating it by the cooling heatexchanger (45, 51), and returning it to the first compressor (2A) andthe second compressor (2B); and the warming operation being continued byactuating the first compressor (2A) in place of the second compressor(2B) if the breakdown of the second compressor (2B) is detected duringthe warming operation.
 6. A refrigeration apparatus comprising: arefrigerant circuit (1E) including first, second and third compressors(2A, 2B, 2C) connected in parallel each other, a heat source side heatexchanger (4), an air-conditioning heat exchanger (41) forair-conditioning the inside of a room, a cooling heat exchanger (45, 51)for cooling the inside of a cold store, and first and second expandingmechanisms (42, 46, 52) for expanding a refrigerant; and breakdowndetecting means (80) for detecting the breakdown of at least the secondcompressor (2B); the refrigeration apparatus being capable of freelyperforming at least a warming operation and a warming/freezingoperation, wherein the warming operation is performed by actuating thesecond compressor (2B) and the third compressor (2C), the warmingoperation being achieved by condensing a refrigerant discharged from thesecond compressor (2B) and the third compressor (2C) by means of theair-conditioning heat exchanger (41), expanding it by the firstexpanding mechanism (42), evaporating it by the heat source side heatexchanger (4), and returning it to the second compressor (2B) and thethird compressor (2C), and further, the warming/freezing operation isperformed by actuating the first compressor (2A) and the secondcompressor (2B), the warming/freezing operation being achieved bycondensing a part of a refrigerant discharged from the first compressor(2A) and the second compressor (2B) by means of the air-conditioningheat exchanger (41) while condensing the residual discharged refrigerantby means of the heat source side heat exchanger (4), expanding both ofthe refrigerants by the second expanding mechanism (46, 52), evaporatingthem by the cooling heat exchanger (45, 51), and returning them to thefirst compressor (2A) and the second compressor (2B); the refrigerantcircuit (1E) further including a refrigerant pipeline (23) forintroducing the refrigerant from pipelines on the suction sides of thefirst compressor (2A) and the second compressor (2B) to a pipeline onthe suction side of the third compressor (2C), and channel switchingmeans (7 a) disposed on the refrigerant pipeline (23); and thewarming/freezing operation being continued by opening the channelswitching means (7 a), and further, actuating the third compressor (2C)in place of the second compressor (2B) if the breakdown of the secondcompressor (2B) is detected during the warming/freezing operation.
 7. Arefrigeration apparatus as claimed in any one of claims 1 to 6, whereinthe cooling heat exchanger includes a refrigerating heat exchanger (45)and a freezing heat exchanger (51); and the refrigerant circuit (1E)includes an auxiliary compressor (53) disposed downstream of thefreezing heat exchanger (51), for reducing the pressure of therefrigerant inside of the freezing heat exchanger (51) lower than thatof the refrigerant inside of the refrigerating heat exchanger (45).
 8. Arefrigeration apparatus as claimed in claim 7, further comprising: abypass passage (59) connected at one end thereof to the discharge sideof the auxiliary compressor (53) and at the other end thereof to thesuction side of the auxiliary compressor (53), for allowing therefrigerant to flow in such a manner as to bypass the auxiliarycompressor (53) if the auxiliary compressor (53) is broken down.